The effect of Si addition on phase separation and soft magnetic properties of Cu0.6(FeCrC)0.4100-xSix (x = 3 and 8) immiscible composites produced by laser induction hybrid cladding (LIHC) has been investigated. The duplex structure of immiscible composites was composed of many Fe-rich particles dispersed within Cu-rich upper layer and large amounts of Cu-rich particles embedded within Fe-rich lower layer. However, the increasing Si addition not only induced the precipitation of intermetallic compound Cu6.69Si within Cu-rich upper layer, but also increased the area of Fe-rich layer, the size of Fe- and Cu-rich particles, as well as the solubility of Si in Fe- and Cu-rich phases. Moreover, the microhardness of Fe- and Cu-rich layers was increased to 747.3HV0.2 and 302.6HV0.2 in the Cu55.2(FeCrC)36.8Si8 immiscible composite, respectively, which was ∼1.6 and ∼1.8 times higher than that in the Cu58.2(FeCrC)38.8Si3 immiscible composite, due to solid-solution strengthening and dispersion strengthening. Compared to the Cu58.2(FeCrC)38.8Si3 immiscible composite, the Cu55.2(FeCrC)36.8Si8 immiscible composite presented a saturated magnetization of 13.7 emu/g, relatively lower coercivity of 24.9 Oe and higher Curie temperature of larger than 400 K due to appearance of ferromagnetic α-Fe(Si) phase. Display omitted •Increasing Si addition induces the precipitation of intermetallic compound Cu6.69Si.•Increasing Si increases the area of Fe-rich layer, and Fe- and Cu-rich particle size.•Increasing Si addition can increase the microhardness of immiscible composites.•Cu55.2(FeCrC)36.8Si8 composite presented a saturated magnetization (13.7 emu/g).•Cu55.2(FeCrC)36.8Si8 composite presented a low coercivity (24.9 Oe).